Next year I am going to move everyone off of POP3 to IMAP for incoming mail. I want to keep everyone’s mail up on the server instead of on there desktop machine. This will give me a better back up plan for employee mail. It would also be one less thing I would have to move off there machine when I upgrade them and one less thing for them to lose if there hard drive goes south on there desktops.

I will be doing hardware Raid 5 off the 3ware card using 5 of the drives for data, that will give me 1TB of space and the other 2 drives I will do Raid 1 for the Os off the raid card on the mother board. With 2 Gigs of Memory this machine should scream.

I’m not sure… seems a bit overkill to me. Unless you’re planning on never upgrading your hardware ever again, or your users have a nasty habit of using their email as a file system complete with 50 MB attachments, you should have way more than enough juice.